1. Field of the Invention
The present invention generally relates to an apparatus for mounting transparent documents. Specifically, the present invention is a securing device for securing a transparent document during scanning processes in a flatbed scanner.
2. Background Description
Nowadays flatbed scanners are fully developed computer accessories available on the consumer market. The flatbed scanner can scan colorful documentation and black-white documentation into computer files in order to preserve ordinary images or pictures. The flatbed scanner can also scan particular transparent documents, such as slides or films, by changing the light path from other direction. The transparent scanning operation can be well done in the same manner as ordinary scanning operation.
In the operation for scanning general colorful or black-white documents, the sizes of the documents usually are regular sizes, such as A4, A3, Letter or B5. The flatbed scanner is therefore comprising a document glass for positioning an original document to be scanned. Thus, for the regular sizes, the user simply follows the instructions, such as placing the original document to a predetermined position of the document glass of the scanner, selecting a corresponding size of the original document, and setting parameters of the scanning conditions in a driver program. The scanner will scan the original document by the settings. The scanner is therefore able to scan different documents by acquiring different settings.
However, in case of scanning transparent documents, for examples films, the sizes of transparent documents are regulated but differing from A3, A4, B4, or Letter size. Actually, the sizes of slides are much smaller than the area of the document glass. Thus, the users can scan several transparent documents at one time in order to save scanning time. Problems are occurring by this kind of operation. The user is usually unable to align several transparent documents on the document glass. Therefore, referring to FIG. 1, it is necessary to preselect the positions of each transparent document from the selection feature provided by the driver program, before main scanning process. By this preselection, the scanner can scan the transparent documents. Nonetheless, the auxiliary process of preselecting transparent documents from the driver program consumes the operation time and causes user's inconvenience.
To solve the above-mentioned problem, a driver software implementing an automatic transparent document locating feature is available on the market. However, it still takes lots time to locate and scan the transparent documents. Because the sizes of transparent documents are regulated, it is still not efficient if a process of preselecting transparent documents' location is needed.
Thus, there is a locating device provided for scanning original objects which have regulated sizes, for example, transparent documents. The locating device is provided for the scanning process in a flatbed scanner. Referring to FIG. 2, the locating device 2 comprises a frame 22 and at least one opening 23. First, the frame 22 is positioned on the document glass 13. Next, transparent documents are placed in the opening 23 (transparent documents not shown) in order. After placing down the cover 12, start the scanning program by a predetermined scanning mode. The scanned images are then acquired.
The frame 22 of the locating device is usually made by soft plastic material. There are several openings as the similar size of transparent documents. However, there is not featured any fixation mechanism in the mentioned locating device. Therefore, the locating device cannot provide precise positions of transparent documents during scanning. Moreover, even though the size of transparent documents is regulated, the thickness of the frame of the transparent documents will vary in different framing brands. The variant thickness of the transparent document frames will cause diffusion of the scanned image because the scanner cannot precisely focus on transparent documents which have different thickness.
In Taiwan Utility Patent (Republic of China Utility Patent) No. 294,428, there is disclosed a fixation device. Once a frame holds several transparent documents, the frame is placed into a holding member. The holding member is then inserted to a dedicated scanner for transparent scanning process. Thus, the holding member needs an upper and a lower portions for holding the frame. In addition, the dedicated scanner must implement a particular apparatus in order to scan transparent documents via a particular method. This operation is too complicated and inconvenient to the user. In addition, because the transparent document is only secured by one clip, the transparent document is able to slip to another position. It causes differences between the actual transparent document position and predetermined position in the driver program. The actual transparent document position therefore cannot be acquired. Further, the focus of the scanner cannot be precisely achieved since the transparent documents are not fully secured in a predetermined position and at a fixed height.